With the rapid development of mobile communication technology, electromagnetic environment gets more and more complicated, which means rigid requirement for design of dual-polarized directional antenna used in mobile communication system should be met. High quality of electrical performance is required for some antennae such as great gain, cross polarization discrimination of the main axis of more than 20 dB, cross polarization discrimination of more than 10 dB, good directionality and beam convergence. In addition, good adaptability to the ambient surroundings, small size, lightweight and aesthetic appearance is also desired. Further, low cost is also desired to win in the competing market.
To a large extent, the radiation element of an array antenna determines much performance of the antenna such as the gain, width of the beam, beam convergence, as well as cross polarization. In design of a base station antenna of high gain, it is required to improve the gain of the antenna radiation element as high as possible in consideration of meeting beam width limitation. The dual polarized radiation oscillator is also required to bear excellent cross polarization property.
A wideband dual polarized antenna oscillator is disclosed in Chinese Utility Patent No. CN201117803Y issued on Sep. 17, 2008. In this patent disclosure, a planar oscillator similar to the invention is manufactured by printed circuit board. The planar oscillator is separated into two parts which are interconnected with each other physically and electrically coupled with each other rather than direct connection. That is, a first surface radiation construction defining the periphery and a second surface radiation construction defining the interior of the planar oscillator. Then, a plurality of through holes is defined in corners of respective oscillator arms at the middle location of the second surface radiation construction. Next, a support body having several grooves defined therein passes through the through holes of the corners provided on the medium base plate and then a feeding cable is bent and welded.
It seems that the above structure is somewhat complex for a person of ordinary skill in the art in view of above heavy description and accordingly, it is inconvenient for this structure to be manufactured.
Additionally, though it is alleged in the above patent disclosure that the characteristics of antenna is enhanced, attention should be paid to weak signal energy due to coupling other than direction connection. In this situation, the inventor seeks for improvement upon the above conventional technology.